/*
 * Copyright (c) 2014, Peter Thorson. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the WebSocket++ Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL PETER THORSON BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#ifndef WEBSOCKETPP_SERVER_ENDPOINT_HPP
#define WEBSOCKETPP_SERVER_ENDPOINT_HPP

#include <websocketpp/endpoint.hpp>

#include <websocketpp/logger/levels.hpp>

#include <websocketpp/common/system_error.hpp>

namespace websocketpp
{

/// Server endpoint role based on the given config
/**
 *
 */
template <typename config>
class server : public endpoint<connection<config>, config>
{
public:
  /// Type of this endpoint
  typedef server<config> type;

  /// Type of the endpoint concurrency component
  typedef typename config::concurrency_type concurrency_type;
  /// Type of the endpoint transport component
  typedef typename config::transport_type transport_type;

  /// Type of the connections this server will create
  typedef connection<config> connection_type;
  /// Type of a shared pointer to the connections this server will create
  typedef typename connection_type::ptr connection_ptr;

  /// Type of the connection transport component
  typedef typename transport_type::transport_con_type transport_con_type;
  /// Type of a shared pointer to the connection transport component
  typedef typename transport_con_type::ptr transport_con_ptr;

  /// Type of the endpoint component of this server
  typedef endpoint<connection_type, config> endpoint_type;

  friend class connection<config>;

  explicit server() : endpoint_type (true)
  {
    endpoint_type::m_alog.write (log::alevel::devel, "server constructor");
  }

  /// Destructor
  ~server<config>() {}

#ifdef _WEBSOCKETPP_DEFAULT_DELETE_FUNCTIONS_
  // no copy constructor because endpoints are not copyable
  server<config> (server<config> &) = delete;

  // no copy assignment operator because endpoints are not copyable
  server<config> &operator= (server<config> const &) = delete;
#endif // _WEBSOCKETPP_DEFAULT_DELETE_FUNCTIONS_

#ifdef _WEBSOCKETPP_MOVE_SEMANTICS_
  /// Move constructor
  server<config> (server<config>  &&o) : endpoint<connection<config>, config>
    (std::move (o) ) {}

#ifdef _WEBSOCKETPP_DEFAULT_DELETE_FUNCTIONS_
  // no move assignment operator because of const member variables
  server<config> &operator= (server<config> && ) = delete;
#endif // _WEBSOCKETPP_DEFAULT_DELETE_FUNCTIONS_

#endif // _WEBSOCKETPP_MOVE_SEMANTICS_

  /// Create and initialize a new connection
  /**
   * The connection will be initialized and ready to begin. Call its start()
   * method to begin the processing loop.
   *
   * Note: The connection must either be started or terminated using
   * connection::terminate in order to avoid memory leaks.
   *
   * @return A pointer to the new connection.
   */
  connection_ptr get_connection()
  {
    return endpoint_type::create_connection();
  }

  /// Starts the server's async connection acceptance loop (exception free)
  /**
   * Initiates the server connection acceptance loop. Must be called after
   * listen. This method will have no effect until the underlying io_service
   * starts running. It may be called after the io_service is already running.
   *
   * Refer to documentation for the transport policy you are using for
   * instructions on how to stop this acceptance loop.
   *
   * @param [out] ec A status code indicating an error, if any.
   */
  void start_accept (lib::error_code &ec)
  {
    if (!transport_type::is_listening() ) {
      ec = error::make_error_code (error::async_accept_not_listening);
      return;
    }

    ec = lib::error_code();
    connection_ptr con = get_connection();

    transport_type::async_accept (
      lib::static_pointer_cast<transport_con_type> (con),
      lib::bind (&type::handle_accept, this, con, lib::placeholders::_1),
      ec
    );

    if (ec && con) {
      // If the connection was constructed but the accept failed,
      // terminate the connection to prevent memory leaks
      con->terminate (lib::error_code() );
    }
  }

  /// Starts the server's async connection acceptance loop
  /**
   * Initiates the server connection acceptance loop. Must be called after
   * listen. This method will have no effect until the underlying io_service
   * starts running. It may be called after the io_service is already running.
   *
   * Refer to documentation for the transport policy you are using for
   * instructions on how to stop this acceptance loop.
   */
  void start_accept()
  {
    lib::error_code ec;
    start_accept (ec);

    if (ec) {
      throw exception (ec);
    }
  }

  /// Handler callback for start_accept
  void handle_accept (connection_ptr con, lib::error_code const &ec)
  {
    if (ec) {
      con->terminate (ec);

      if (ec == error::operation_canceled) {
        endpoint_type::m_elog.write (log::elevel::info,
                                     "handle_accept error: " + ec.message() );
      } else {
        endpoint_type::m_elog.write (log::elevel::rerror,
                                     "handle_accept error: " + ec.message() );
      }
    } else {
      con->start();
    }

    lib::error_code start_ec;
    start_accept (start_ec);

    if (start_ec == error::async_accept_not_listening) {
      endpoint_type::m_elog.write (log::elevel::info,
                                   "Stopping acceptance of new connections because the underlying transport is no longer listening.");
    } else if (start_ec) {
      endpoint_type::m_elog.write (log::elevel::rerror,
                                   "Restarting async_accept loop failed: " + ec.message() );
    }
  }
};

} // namespace websocketpp

#endif //WEBSOCKETPP_SERVER_ENDPOINT_HPP
